Abrasive cutoff machine



`Maly? 21, 1946. L. L. vADNAls 2,400,794

ABRSIVE CUT-OFF MACHINE Filed May 1o.' 1944 Patented May 21, 1946` ABRASIVE CUTOFF MACHINE vLeo L. Vadnais, St. Paul, Minn., assignor to Herzog Iron Works, Inc., St. Paul, Minn., a'corpo ration of Minnesota Application May 10, 1944, Serial No. 534,880

2 Claims.

This invention relates to machines for cutting materials wherein the cutting operation produces considerable heat and the material being cut is subjected to considerable expansion Abecause of the heat.

The invention is particularly adaptable to machine tools known as cut-01T machines wherein work such as metal stock is fed into cutting position and where the cutting position is determined by a stop device which is adapted topbe engaged bythe work. One such machine is known in the trade-as, an abrasive cut-olf machine which utilizes a thin disc of abrasive material which is rotated rapidly to cut through stock such as metal bars and rods. The abrasive discs arerelatively thin and incapable of withstanding any great amount of strain or distortion.

It has been found that when a piece of metal stock such as a bar rod or pipe is placed upon a support and moved into engagement with a stop device positioned to determine the size of the piece to be cut off there is considerable expansion of the metal due to the heat generated by the abrasive disc. Frequently pieces are cut from relatively long rods or bars and when the heat produced in the cutting operation expands the metal the weight of the bar and the fact that it is held in position by a stop will cause the expanding metal to close in against the sides of the cutting disc with a bending action and the disc will break.

It is a general object of the invention to provide means for compensating for the expansive action of the heated work piece so that there will be no tendency for the cutting disc to bind and break.

The above and other objects and advantages of the inventionwill more fully appear from the following description made in connection with the accompanying drawing, wherein like refer-- ence characters refer to the same parts throughout the views, and, in which:

Fig. 1 is a front elevational View of a cut-oif machine having my invention incorporated therewith;

Fig. 2 is a side elevation of the machine;

Fig. 3 is anenlarged fragmentary detail partially in section and partially in front elevation; and

Fig. 4 is an enlarged fragmentary top view of the stop device.

In Figs. 1 and 2 there is shown a cut-off machine having a base 5 which is adapted to be supported in any suitable manner. At the rear of the base 5 is a bracket 5 adapted to pivotally support a motor mounting 'I having lugs 8. A pivot shaft 9 extends through the bracket 6 and the lugs 8. The motor mounting 'I has an electric motor I suitably secured thereto- The mounting 'I has a forwardly extending arm II to which is connected a casing I2 which serves as a housing for a belt I3 driven by a pulley I4 on the motor shaft I5. The forward end of the housing I2 has a countershaft IB journalled therein and extending outwardly from one side thereof. The eountershaft I 6 also extends through the forward end of the motor mounting extension Il. As viewed in Figs. 1 and 3, the countershaft I6 has on its left end an abrasive disc I1, the shaft I6 and disc I'I being driven by the belt I3 which moves over a pulley I8 on said countershaft IE. A suitable guard indicated generally at I9 is provided to shield the abrasive disc I1 and said shield is provided with a work receiving cut-out 20 at its medial lower portion.

An operating handle 2I extends forwardly from the housing I2 and by means of the handle the housing I2 and abrasive wheel I I are adapted to be moved upwardly and downwardly about the pivot pin 9 which connects the motor support l to the bracket 6 on the base 5. As best viewed in Fig. 2 the motor is mounted in an off-balance position so that the housing I2 and abrasive wheel I'I normally will lie in upwardly spaced relation to the base 5. The details of the foregoing mechanism are conventional and a structure of that general type is produced by the Delta Manufacturing Company of Milwaukee, Wisconsin.

Mounted on the base 5 are guide rails 22 and 23 which lie at either side of the abrasive cut-oi disc Il. As viewed in Figs. 1 and 3, I provide a stop element 24 which is pivotally connecte-d to bracket 26 movably secured to the guide rail 23 by means of thumb screws 2l. The left hand end of the stop member 24 constitutes a head 23 having a downward extension as shown in Figs. 1 and 3 and having an end surface 29 which is closer to the pivot 25 at its lower portion and is spaced progressively further from the pivot 25 as said surface 29 approaches the top of the head 28. i

Mounted on casing I2 is a bracket 30 which has a portion 3| extending above and parallel to the guide rail 23. An arm 32 extends downwardly from the bracket arm 3l and said arms 3| and 32 are slotted as indicated at 33 and 34 to receive a nutted bolt 35. By reason of the slots 33 and 34 the arm 32 can be adjusted lon- .gitudinally and vertically relative to the bracket arm 3|. The lower end of the arm 32 is bent 251. The stop, of course, is positioned so that the abrasive disc I1 will cut off a desired length of the rod 31. With the rod of metal stock in position for cutting the abrasive disc is swung down into contact with the rod and the cuttingV operation is commenced. As the cutting proceeds and the disc I1 passes downwardly through the rod 31 the contact block 36 on the' downwardly extending arm 32 will come into engagement with the stop member 25 on the right hand Yside of the stop pivot bolt 25 as best indicated in Fig. 3. This will cause the work engaging head on the stop member 2li to rise out of engagement with the end of the rod or bar 31. The device is so adjusted that the abrasive wheel I1 will have cut into the rod 31 suiiciently to produce the remainder of the cut at the desired point but the rod is free to expand longitudinally under the influence of heat generated in the cutting operation.

YThe above described shape of the surface 29 on the stop 24 is designed to permit proper release or disengagement from the rod 31 even though rods Voi different widths might be used.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the various parts without departing from the scope of my invention.

What I claim is:

1. In a cut-off machine having a movable cutter and a work support relative to which said cutter can be shited, apivoted stop device for determining the position of work on said support and relative to said cutter, said stop device having a work engaging surface disposed progressively inwardly toward the pivotal axis of said stop device, and a stop actuator for shifting said stop device about its axis and responsive to movement of said cutter.

2. In a cut-off machine having a movable cutter and a .work support to which said cutter can be shifted, a stop device for determining the position of the work on said support and relative to said cutter, said stopdevice being movable toward and away Yfrom said support and work lying thereon, said stop devicehaving a work engaging surface disposed progressively downwardly and away from the adjacent point of location of said work, and a stop actuator for shifting said stop device toward and away from said work support and responsive to movement of said cutter.

LEO L. VADNAS. 

